The corneal ulcer one-touch study: a simplified microbiological specimen collection method

Traditional corneal specimen collection for infectious keratitis involves multiple samples and specialized media, which can be complex and resource-intensive. Prior research has shown that this multi-sample approach is effective but may be impractical in some clinical environments. No prior work had resolved whether a simplified single-sample method could maintain diagnostic accuracy. This gap motivated the evaluation of a new device designed to streamline specimen collection. The multi-sample method typically includes chocolate agar, blood agar, Sabouraud agar, and broth cultures. However, access to these materials may be limited in community settings. Researchers have proposed that a single-sample device could reduce the burden on clinicians while preserving diagnostic outcomes. The challenge remains to determine if such a device can match traditional methods in culture positivity rates.

The aim of this study was to assess whether a new single-sample device could replace the traditional multi-sample approach for corneal specimen collection in infectious keratitis. Infectious keratitis requires accurate microbiological testing to guide treatment. The multi-sample method is effective but may be cumbersome for some practitioners. This study sought to evaluate the device's performance in terms of culture positivity rates. Researchers compared the device to the standard multi-sample method in a clinical setting. The study focused on patients meeting traditional diagnostic criteria for corneal specimen collection. The goal was to determine if the device could simplify the process without compromising diagnostic accuracy. A key question was whether the device could achieve comparable results to the multi-sample approach. The study aimed to provide evidence for a more accessible diagnostic method.

The study used a prospective, diagnostic test evaluation design to compare a new single-sample device with the traditional multi-sample method. Patients with suspected infectious keratitis were enrolled in an institutional study. Participants were randomized to the order of specimen collection using either the ESwab device or direct plating on chocolate agar. All patients received standard samples including blood agar, Gram stain, Sabouraud agar, thioglycolate broth, and brain heart infusion broth. The specimens were analyzed separately by the laboratory in a masked fashion. Culture positivity rate was the primary outcome measure. The study included 81 eyes from 80 consecutive patients. The order of specimen collection did not affect the results, indicating the device's reliability.

Culture positivity rates were 70% for the multi-sample method and 69% for the ESwab device, with a 75% agreement rate between the two. The ESwab device demonstrated a sensitivity of 84% (95% CI: 72%-93%) and a specificity of 67% (95% CI: 45%-84%). Positive and negative predictive values were 86% (95% CI: 74%-94%) and 64% (95% CI: 43%-82%), respectively. The device did not show a significant difference in culture positivity based on the order of specimen collection. These results suggest the device is comparable to the traditional method in diagnostic accuracy. The device's performance was consistent across different types of microbial cultures. The study found no evidence that the device compromised the quality of diagnostic results. The device's ease of use may make it a practical alternative in clinical settings.

The study found that the single-sample ESwab device is a viable alternative to the traditional multi-sample method for corneal specimen collection. The device achieved a comparable culture positivity rate of 69% versus 70% for the multi-sample approach. The 75% agreement rate between the two methods indicates strong concordance in diagnostic outcomes. The device's sensitivity and specificity suggest it can reliably detect infectious keratitis. The study supports the use of the device in community settings where traditional materials may be limited. The device's ease of use may improve accessibility for ophthalmologists without specialized microbiological training. The findings do not suggest a need for additional testing beyond what is standard in microbiological culture. The device's performance was consistent regardless of the order of specimen collection.